Managing Cloud Zones

ABSTRACT

Methods and systems for managing cloud zones are described herein. A management server for a cloud of computing resources may add private zones to the cloud. The private zones may contain computers owned and operated by a user of the cloud, such as a cloud customer, rather than the cloud operator. The management server may manage the computing resources in the private zone by sending commands to an agent, which in turn relays the management server&#39;s commands to the individual computing resources. The agent may be authenticated using a token.

FIELD

This application generally relates to creating and managing virtualmachines. In particular, this application relates to provisioningvirtual machines on a cloud customer's physical resources by adding thecloud customer's physical resources to a cloud as a private zone.

BACKGROUND

Traditionally, personal computers included operating systems,applications, and user settings for a single user. Personal computerswere generally both used and managed by their owners. However, manyorganizations are now using clouds of computing resources to fulfilltheir computing needs. The clouds of computing resources generally allowfor the operating systems, applications, and user settings of multipleusers to be included on a single physical machine. Desktopvirtualization technology allows multiple instances of an operatingsystem to be kept separate, so the activities of one user may not affectthe experience of other users. Cloud computing environments allow forcomputers owned by the cloud operator to be managed by the cloudoperator but used by cloud users, who may be customers of the cloudoperator.

SUMMARY

In light of the foregoing background, the following presents asimplified summary of the present disclosure in order to provide a basicunderstanding of some aspects described herein. This summary is not anextensive overview, and it is not intended to identify key or criticalelements or to delineate the scope of the claims. The following summarymerely presents various described aspects in a simplified form as aprelude to the more detailed description provided below.

According to one aspect of the disclosure, a management server for acloud of physical computing resources may manage private resources of acloud customer in addition to the resources of the cloud operator. Theprivate resources may be organized into one or more private zones of thecloud.

According to another aspect of the disclosure, one or more of theprivate zones may be located behind a firewall, thereby making theresources inaccessible to the management server. One or more agents mayinitiate a communications session with the management server. Thecommunications session may be maintained continuously, thereby enablingcommunications from the management server to reach the agent. The agentmay relay communications from the management server to the appropriatephysical resources.

According to a still further aspect of the disclosure, the managementserver may provide a token for use by an authorized agent. Themanagement server may authenticate an agent using the token beforemanaging the resources behind the agent.

BRIEF DESCRIPTION OF THE DRAWINGS

Having thus described aspects of the disclosure in general terms,reference will now be made to the accompanying drawings, which are notnecessarily drawn to scale, and wherein:

FIG. 1 illustrates an example operating environment in which variousaspects of the disclosure may be implemented.

FIG. 2 illustrates a computing device that may be used in accordancewith one or more illustrative aspects described herein.

FIG. 3 illustrates a computing device that may be used in accordancewith one or more illustrative aspects described herein.

FIG. 4 is a block diagram that depicts embodiments of a virtualizationserver in accordance with one or more illustrative aspects describedherein.

FIG. 5 illustrates an example of a cloud computing environment.

FIG. 6 illustrates an example of a user interface that may be providedby a management server.

FIG. 7 illustrates a cloud computing environment that includes a privatezone.

FIG. 8 illustrates a method for adding a private zone to a cloud.

DETAILED DESCRIPTION

In the following description of the various embodiments, reference ismade to the accompanying drawings, which form a part hereof, and inwhich is shown by way of illustration various embodiments in whichaspects described herein may be practiced. It is to be understood thatother embodiments may be utilized and structural and functionalmodifications may be made without departing from the scope and spirit ofthe present disclosure.

As will be appreciated by one of skill in the art upon reading thefollowing disclosure, various aspects described herein may be embodiedas a method, a data processing system, or a computer program product.Accordingly, those aspects may take the form of an entirely hardwareembodiment, an entirely software embodiment or an embodiment combiningsoftware and hardware aspects. Furthermore, such aspects may take theform of a computer program product stored by one or morecomputer-readable storage media having computer-readable program code,or instructions, embodied in or on the storage media. Any suitablecomputer readable storage media may be utilized, including hard disks,CD-ROMs, optical storage devices, magnetic storage devices, and/or anycombination thereof. In addition, various signals representing data orevents as described herein may be transferred between a source and adestination in the form of electromagnetic waves traveling throughsignal-conducting media such as metal wires, optical fibers, and/orwireless transmission media (e.g., air and/or space).

FIG. 1 illustrates an example block diagram of a generic computingdevice 101 (e.g., a computer server 106 a) in an example computingenvironment 100 that may be used according to one or more illustrativeembodiments of the disclosure. According to one or more aspects, genericcomputing device 101 may be a server 106 a in a single-server ormulti-server desktop virtualization system (e.g., a cloud system)configured to provide virtual machines for client access devices. Thegeneric computing device 101 may have a processor 103 for controllingoverall operation of the server and its associated components, includingrandom access memory (RAM) 105, read-only memory (ROM) 107, input/output(I/O) module 109, and memory 115.

I/O module 109 may include a mouse, keypad, touch screen, scanner,optical reader, and/or stylus (or other input device(s)) through which auser of generic computing device 101 may provide input, and may alsoinclude one or more of a speaker for providing audio output and a videodisplay device for providing textual, audiovisual, and/or graphicaloutput. Software may be stored within memory 115 and/or other storage toprovide instructions to processor 103 for enabling generic computingdevice 101 to perform various functions. For example, memory 115 maystore software used by the generic computing device 101, such as anoperating system 117, application programs 119, and an associateddatabase 121. Alternatively, some or all of the computer executableinstructions for generic computing device 101 may be embodied inhardware or firmware (not shown).

The generic computing device 101 may operate in a networked environmentsupporting connections to one or more remote computers, such asterminals 140 (also referred to as client devices). The terminals 140may be personal computers or servers that include many or all of theelements described above with respect to the generic computing device101. The network connections depicted in FIG. 1 include a local areanetwork (LAN) 125 and a wide area network (WAN) 129, but may alsoinclude other networks. When used in a LAN networking environment, thegeneric computing device 101 may be connected to the LAN 125 through anetwork interface or adapter 123. When used in a WAN networkingenvironment, the generic computing device 101 may include a modem 127 orother network interface for establishing communications over the WAN129, such as computer network 130 (e.g., the Internet). It will beappreciated that the network connections shown are illustrative andother means of establishing a communications link between the computersmay be used.

Generic computing device 101 and/or terminals 140 may also be mobileterminals (e.g., mobile phones, smartphones, PDAs, notebooks, etc.)including various other components, such as a battery, speaker, andantennas (not shown).

The disclosure is operational with numerous other general purpose orspecial purpose computing system environments or configurations.Examples of well-known computing systems, environments, and/orconfigurations that may be suitable for use with the disclosure include,but are not limited to, personal computers, server computers, hand-heldor laptop devices, multiprocessor systems, microprocessor-based systems,set top boxes, programmable consumer electronics, network PCs,minicomputers, mainframe computers, distributed computing environmentsthat include any of the above systems or devices, and the like.

As shown in FIG. 1, one or more client devices 140 may be incommunication with one or more servers 106 a-106 n (generally referredto herein as “server(s) 106”). In one embodiment, the computingenvironment 100 can include an appliance installed between the server(s)106 and client machine(s) 140. This appliance can manage client/serverconnections, and in some cases can load balance client connectionsamongst a plurality of backend servers 106.

The client machine(s) 140 can in some embodiment be referred to as asingle client machine 140 or a single group of client machines 140,while server(s) 106 may be referred to as a single server 106 or asingle group of servers 106. In one embodiment a single client machine140 communicates with more than one server 106, while in anotherembodiment a single server 106 communicates with more than one clientmachine 140. In yet another embodiment, a single client machine 140communicates with a single server 106.

A client machine 140 can, in some embodiments, be referenced by any oneof the following terms: client machine(s) 140; client(s); clientcomputer(s); client device(s); client computing device(s); localmachine; remote machine; client node(s); endpoint(s); endpoint node(s);or a second machine. The server 106, in some embodiments, may bereferenced by any one of the following terms: server(s), local machine;remote machine; server farm(s), host computing device(s), or a firstmachine(s).

In one embodiment, the client machine 140 may be a virtual machine. Thevirtual machine may be any virtual machine, while in some embodimentsthe virtual machine may be any virtual machine managed by a hypervisordeveloped by Citrix Systems, IBM, VMware, or any other hypervisor. Insome aspects, the virtual machine may be managed by a hypervisor, whilein aspects the virtual machine may be managed by a hypervisor executingon a server 106 or a hypervisor executing on a client 140.

The client machine 140 may execute, operate or otherwise provide anapplication that can be any one of the following: software; a program;executable instructions; a virtual machine; a hypervisor; a web browser;a web-based client; a client-server application; a thin-client computingclient; an ActiveX control; a Java applet; software related to voiceover internet protocol (VoIP) communications like a soft IP telephone;an application for streaming video and/or audio; an application forfacilitating real-time-data communications; a HTTP client; a FTP client;an Oscar client; a Telnet client; or any other set of executableinstructions. Still other embodiments include a client device 140 thatdisplays application output generated by an application remotelyexecuting on a server 106 or other remotely located machine. In theseembodiments, the client device 140 can display the application output inan application window, a browser, or other output window. In oneexample, the application is a desktop, while in other examples theapplication is an application that generates a desktop. A desktop mayinclude a graphical shell providing a user interface for an instance ofan operating system in which local and/or remote applications can beintegrated. Applications, as used herein, are programs that executeafter an instance of an operating system (and, optionally, also thedesktop) has been loaded.

The server 106, in some embodiments, executes a remote presentationclient or other client or program that uses a thin-client orremote-display protocol to capture display output generated by anapplication executing on a server 106 and transmits the applicationdisplay output to a remote client 140. The thin-client or remote-displayprotocol can be any one of the following protocols: the IndependentComputing Architecture (ICA) protocol manufactured by Citrix Systems,Inc. of Ft. Lauderdale, Fla.; or the Remote Desktop Protocol (RDP)manufactured by the Microsoft Corporation of Redmond, Wash.

The computing environment can include more than one server 106A-106Nsuch that the servers 106A-106N are logically grouped together into aserver farm 106, for example, in a cloud computing environment. Theserver farm 106 can include servers 106 that are geographicallydispersed and logically grouped together in a server farm 106, orservers 106 that are located proximate to each other and logicallygrouped together in a server farm 106. Geographically dispersed servers106A-106N within a server farm 106 can, in some embodiments, communicateusing a WAN, MAN, or LAN, where different geographic regions can becharacterized as: different continents; different regions of acontinent; different countries; different states; different cities;different campuses; different rooms; or any combination of the precedinggeographical locations. In some embodiments the server farm 106 may beadministered as a single entity, while in other embodiments the serverfarm 106 can include multiple server farms 106.

In some embodiments, a server farm 106 can include servers 106 thatexecute a substantially similar type of operating system platform (e.g.,WINDOWS NT, manufactured by Microsoft Corp. of Redmond, Washington,UNIX, LINUX, or SNOW LEOPARD.) In other embodiments, the server farm 106can include a first group of servers 106 that execute a first type ofoperating system platform, and a second group of servers 106 thatexecute a second type of operating system platform. The server farm 106,in other embodiments, can include servers 106 that execute differenttypes of operating system platforms.

The server 106, in some embodiments, can be any server type. In otherembodiments, the server 106 can be any of the following server types: afile server; an application server; a web server; a proxy server; anappliance; a network appliance; a gateway; an application gateway; agateway server; a virtualization server; a deployment server; a SSL VPNserver; a firewall; a web server; an application server or as a masterapplication server; a server 106 executing an active directory; or aserver 106 executing an application acceleration program that providesfirewall functionality, application functionality, or load balancingfunctionality. In some embodiments, a server 106 may be a RADIUS serverthat includes a remote authentication dial-in user service. Inembodiments where the server 106 comprises an appliance, the server 106can be an appliance manufactured by any one of the followingmanufacturers: the Citrix Application Networking Group; Silver PeakSystems, Inc.; Riverbed Technology, Inc.; F5 Networks, Inc.; or JuniperNetworks, Inc. Some embodiments include a first server 106A thatreceives requests from a client machine 140, forwards the request to asecond server 106 n, and responds to the request generated by the clientmachine 140 with a response from the second server 106 n. The firstserver 106A can acquire an enumeration of applications available to theclient machine 140 and well as address information associated with anapplication server 106 hosting an application identified within theenumeration of applications. The first server 106A can then present aresponse to the client's request using a web interface, and communicatedirectly with the client 140 to provide the client 140 with access to anidentified application.

The server 106 can, in some embodiments, execute any one of thefollowing applications: a thin-client application using a thin-clientprotocol to transmit application display data to a client; a remotedisplay presentation application; any portion of the CITRIX ACCESS SUITEby Citrix Systems, Inc. like the METAFRAME or CITRIX PRESENTATIONSERVER; MICROSOFT WINDOWS Terminal Services manufactured by theMicrosoft Corporation; or an ICA client, developed by Citrix Systems,Inc. Another embodiment includes a server 106 that is an applicationserver such as: an email server that provides email services such asMICROSOFT EXCHANGE manufactured by the Microsoft Corporation; a web orInternet server; a desktop sharing server; a collaboration server; orany other type of application server. Still other embodiments include aserver 106 that executes any one of the following types of hostedservers applications: GOTOMEETING provided by Citrix Online Division,Inc.; WEBEX provided by WebEx, Inc. of Santa Clara, Calif.; or MicrosoftOffice LIVE MEETING provided by Microsoft Corporation.

Client machines 140 can, in some embodiments, be a client node thatseeks access to resources provided by a server 106. In otherembodiments, the server 106 may provide clients 140 or client nodes withaccess to hosted resources. The server 106, in some embodiments,functions as a master node such that it communicates with one or moreclients 140 or servers 106. In some embodiments, the master node canidentify and provide address information associated with a server 106hosting a requested application, to one or more clients 140 or servers106. In still other embodiments, the master node can be a server farm106, a client 140, a cluster of client nodes 140, or an appliance.

One or more clients 140 and/or one or more servers 106 can transmit dataover a network 130 installed between machines and appliances within thecomputing environment 100. The network 130 can comprise one or moresub-networks, and can be installed between any combination of theclients 140, servers 106, computing machines and appliances includedwithin the computing environment 100. In some embodiments, the network130 can be: a local-area network (LAN); a metropolitan area network(MAN); a wide area network (WAN); a primary network 104 comprised ofmultiple sub-networks located between the client machines 140 and theservers 106; a primary public network 130 (e.g., the Internet) with aprivate sub-network; a primary private network 130 with a publicsub-network; or a primary private network 130 with a privatesub-network. Still further embodiments include a network 130 that can beany of the following network types: a point to point network; abroadcast network; a telecommunications network; a data communicationnetwork; a computer network; an ATM (Asynchronous Transfer Mode)network; a SONET (Synchronous Optical Network) network; a SDH(Synchronous Digital Hierarchy) network; a wireless network; a wirelinenetwork; or a network that includes a wireless link where the wirelesslink can be an infrared channel or satellite band. The network topologyof the network 130 can differ within different embodiments, possiblenetwork topologies include: a bus network topology; a star networktopology; a ring network topology; a repeater-based network topology; ora tiered-star network topology. Additional embodiments may include anetwork of mobile telephone networks that use a protocol to communicateamong mobile devices, where the protocol can be any one of thefollowing: AMPS; TDMA; CDMA; GSM; GPRS UMTS; or any other protocol ableto transmit data among mobile devices.

Illustrated in FIG. 2 is an embodiment of a computing device 200, wherethe client machine 140 and server 106 illustrated in FIG. 1 may bedeployed as and/or executed on any embodiment of the computing device200 illustrated and described herein. Included within the computingdevice 200 is a system bus 250 that communicates with the followingcomponents: a central processing unit 221; a main memory 222; storagememory 228; an input/output (I/O) controller 223; display devices224A-224N; an installation device 216; and a network interface 218. Inone embodiment, the storage memory 228 includes: an operating system,software routines, and a client agent 220. The I/O controller 223, insome embodiments, is further connected to a keyboard 226, and a pointingdevice 227. Other embodiments may include an I/O controller 223connected to more than one input/output device 230A-230N.

FIG. 3 illustrates one embodiment of a computing device 300, where theclient machine 140 and server 106 illustrated in FIG. 1 can be deployedas and/or executed on any embodiment of the computing device 300illustrated and described herein. Included within the computing device300 is a system bus 350 that communicates with the following components:a bridge 370, and a first I/O device 330 a. In another embodiment, thebridge 370 is in further communication with the main central processingunit 321, where the central processing unit 321 can further communicatewith a second I/O device 330 b, a main memory 322, and a cache memory340. Included within the central processing unit 321, are I/O ports, amemory port 303, and a main processor.

Embodiments of the computing machine 300 can include a centralprocessing unit 321 characterized by any one of the following componentconfigurations: logic circuits that respond to and process instructionsfetched from the main memory unit 322; a microprocessor unit, such as:those manufactured by Intel Corporation; those manufactured by MotorolaCorporation; those manufactured by Transmeta Corporation of Santa Clara,Calif.; the RS/6000 processor such as those manufactured byInternational Business Machines; a processor such as those manufacturedby Advanced Micro Devices; or any other combination of logic circuits.Still other embodiments of the central processing unit 322 may includeany combination of the following: a microprocessor, a microcontroller, acentral processing unit with a single processing core, a centralprocessing unit with two processing cores, or a central processing unitwith more than one processing core.

While FIG. 3 illustrates a computing device 300 that includes a singlecentral processing unit 321, in some embodiments the computing device300 can include one or more processing units 321. In these embodiments,the computing device 300 may store and execute firmware or otherexecutable instructions that, when executed, direct the one or moreprocessing units 321 to simultaneously execute instructions or tosimultaneously execute instructions on a single piece of data. In otherembodiments, the computing device 300 may store and execute firmware orother executable instructions that, when executed, direct the one ormore processing units to each execute a section of a group ofinstructions. For example, each processing unit 321 may be instructed toexecute a portion of a program or a particular module within a program.

In some embodiments, the processing unit 321 can include one or moreprocessing cores. For example, the processing unit 321 may have twocores, four cores, eight cores, etc. In one embodiment, the processingunit 321 may comprise one or more parallel processing cores. Theprocessing cores of the processing unit 321, may in some embodimentsaccess available memory as a global address space, or in otherembodiments, memory within the computing device 300 can be segmented andassigned to a particular core within the processing unit 321. In oneembodiment, the one or more processing cores or processors in thecomputing device 300 can each access local memory. In still anotherembodiment, memory within the computing device 300 can be shared amongstone or more processors or processing cores, while other memory can beaccessed by particular processors or subsets of processors. Inembodiments where the computing device 300 includes more than oneprocessing unit, the multiple processing units can be included in asingle integrated circuit (IC). These multiple processors, in someembodiments, can be linked together by an internal high speed bus, whichmay be referred to as an element interconnect bus.

In embodiments where the computing device 300 includes one or moreprocessing units 321, or a processing unit 321 including one or moreprocessing cores, the processors can execute a single instructionsimultaneously on multiple pieces of data (SIMD), or in otherembodiments can execute multiple instructions simultaneously on multiplepieces of data (MIMD). In some embodiments, the computing device 100 caninclude any number of SIMD and MIMD processors.

The computing device 300, in some embodiments, can include a graphicsprocessor or a graphics processing unit (Not Shown). The graphicsprocessing unit can include any combination of software and hardware,and can further input graphics data and graphics instructions, render agraphic from the inputted data and instructions, and output the renderedgraphic. In some embodiments, the graphics processing unit can beincluded within the processing unit 321. In other embodiments, thecomputing device 300 can include one or more processing units 321, whereat least one processing unit 321 is dedicated to processing andrendering graphics.

One embodiment of the computing machine 300 includes a centralprocessing unit 321 that communicates with cache memory 340 via asecondary bus also known as a backside bus, while another embodiment ofthe computing machine 300 includes a central processing unit 321 thatcommunicates with cache memory via the system bus 350. The local systembus 350 can, in some embodiments, also be used by the central processingunit to communicate with more than one type of I/O device 330 a-330 n.In some embodiments, the local system bus 350 can be any one of thefollowing types of buses: a VESA VL bus; an ISA bus; an EISA bus; aMicroChannel Architecture (MCA) bus; a PCI bus; a PCI-X bus; aPCI-Express bus; or a NuBus. Other embodiments of the computing machine300 include an I/O device 330 a-330 n that includes a video display 224that communicates with the central processing unit 321. Still otherversions of the computing machine 300 include a processor 321 connectedto an I/O device 330 a-330 n via any one of the following connections:HyperTransport, Rapid I/O, or InfiniBand. Further embodiments of thecomputing machine 300 include a processor 321 that communicates with oneI/O device 330 a using a local interconnect bus and a second I/O device330 b using a direct connection.

The computing device 300, in some embodiments, includes a main memoryunit 322 and cache memory 340. The cache memory 340 can be any memorytype, and in some embodiments can be any one of the following types ofmemory: SRAM; BSRAM; or EDRAM. Other embodiments include cache memory340 and a main memory unit 322 that can be any one of the followingtypes of memory: Static random access memory (SRAM), Burst SRAM orSynchBurst SRAM (BSRAM); Dynamic random access memory (DRAM); Fast PageMode DRAM (FPM DRAM); Enhanced DRAM (EDRAM), Extended Data Output RAM(EDO RAM); Extended Data Output DRAM (EDO DRAM); Burst Extended DataOutput DRAM (BEDO DRAM); Enhanced DRAM (EDRAM); synchronous DRAM(SDRAM); JEDEC SRAM; PC100 SDRAM; Double Data Rate SDRAM (DDR SDRAM);Enhanced SDRAM (ESDRAM); SyncLink DRAM (SLDRAM); Direct Rambus DRAM(DRDRAM); Ferroelectric RAM (FRAM); or any other type of memory. Furtherembodiments include a central processing unit 321 that can access themain memory 322 via: a system bus 350; a memory port 303; or any otherconnection, bus or port that allows the processor 321 to access memory322.

One embodiment of the computing device 200/300 provides support for anyone of the following installation devices 216: a CD-ROM drive, a CD-R/RWdrive, a DVD-ROM drive, tape drives of various formats, USB device, abootable medium, a bootable CD, a bootable CD for GNU/Linux distributionsuch as KNOPPIX®, a hard-drive or any other device suitable forinstalling applications or software. Applications can in someembodiments include a client agent 220, or any portion of a client agent220. The computing device 200/300 may further include a storage device228 that can be either one or more hard disk drives, or one or moreredundant arrays of independent disks; where the storage device isconfigured to store an operating system, software, programsapplications, or at least a portion of the client agent 220. A furtherembodiment of the computing device 200, 300 includes an installationdevice 216 that is used as the storage device 228.

The computing device 200, 300 may further include a network interface218 to interface to a Local Area Network (LAN), Wide Area Network (WAN)or the Internet through a variety of connections including, but notlimited to, standard telephone lines, LAN or WAN links (e.g., 802.11,T1, T3, 56 kb, X.25, SNA, DECNET), broadband connections (e.g., ISDN,Frame Relay, ATM, Gigabit Ethernet, Ethernet-over-SONET), wirelessconnections, or some combination of any or all of the above. Connectionscan also be established using a variety of communication protocols(e.g., TCP/IP, IPX, SPX, NetBIOS, Ethernet, ARCNET, SONET, SDH, FiberDistributed Data Interface (FDDI), RS232, RS485, IEEE 802.11, IEEE802.11a, IEEE 802.11b, IEEE 802.11g, CDMA, GSM, WiMax and directasynchronous connections). One version of the computing device 200, 300includes a network interface 218 able to communicate with additionalcomputing devices 200′, 300′ via any type and/or form of gateway ortunneling protocol such as Secure Socket Layer (SSL) or Transport LayerSecurity (TLS), or the Citrix Gateway Protocol manufactured by CitrixSystems, Inc. Versions of the network interface 218 can comprise any oneof: a built-in network adapter; a network interface card; a PCMCIAnetwork card; a card bus network adapter; a wireless network adapter; aUSB network adapter; a modem; or any other device suitable forinterfacing the computing device 200, 300 to a network capable ofcommunicating and performing the methods and systems described herein.

Embodiments of the computing device 200, 300 include any one of thefollowing I/O devices 230 a-230 n: a keyboard 226; a pointing device227; mice; trackpads; an optical pen; trackballs; microphones; drawingtablets; video displays; speakers; inkjet printers; laser printers; anddye-sublimation printers; or any other input/output device able toperform the methods and systems described herein. An I/O controller 223may in some embodiments connect to multiple I/O devices 230 a-230 n tocontrol the one or more I/O devices. Some embodiments of the I/O devices230 a-230 n may be configured to provide storage or an installationmedium 216, while others may provide a universal serial bus (USB)interface for receiving USB storage devices such as the USB Flash Driveline of devices manufactured by Twintech Industry, Inc. Still otherembodiments include an I/O device 230 that may be a bridge between thesystem bus 250 and an external communication bus, such as: a USB bus; anApple Desktop Bus; an RS-232 serial connection; a SCSI bus; a FireWirebus; a FireWire 800 bus; an Ethernet bus; an AppleTalk bus; a GigabitEthernet bus; an Asynchronous Transfer Mode bus; a HIPPI bus; a SuperHIPPI bus; a SerialPlus bus; a SCl/LAMP bus; a FibreChannel bus; or aSerial Attached small computer system interface bus.

In some embodiments, the computing machine 200, 300 can connect tomultiple display devices 224 a-224 n, in other embodiments the computingdevice 100 can connect to a single display device 224, while in stillother embodiments the computing device 200, 300 connects to displaydevices 224 a-224 n that are the same type or form of display, or todisplay devices that are different types or forms. Embodiments of thedisplay devices 224 a-224 n can be supported and enabled by thefollowing: one or multiple I/O devices 230 a-230 n; the I/O controller223; a combination of I/O device(s) 230 a-230 n and the I/O controller223; any combination of hardware and software able to support a displaydevice 224 a-224 n; any type and/or form of video adapter, video card,driver, and/or library to interface, communicate, connect or otherwiseuse the display devices 224 a-224 n. The computing device 200, 300 mayin some embodiments be configured to use one or multiple display devices224A-224N, these configurations include: having multiple connectors tointerface to multiple display devices 224A-224N; having multiple videoadapters, with each video adapter connected to one or more of thedisplay devices 224A-224N; having an operating system configured tosupport multiple displays 224A-224N; using circuits and softwareincluded within the computing device 200 to connect to and use multipledisplay devices 224A-224N; and executing software on the main computingdevice 200 and multiple secondary computing devices to enable the maincomputing device 200 to use a secondary computing device's display as adisplay device 224A-224N for the main computing device 200. Still otherembodiments of the computing device 200 may include multiple displaydevices 224A-224N provided by multiple secondary computing devices andconnected to the main computing device 200 via a network.

In some embodiments, the computing machine 200 can execute any operatingsystem, while in other embodiments the computing machine 200 can executeany of the following operating systems: versions of the MICROSOFTWINDOWS operating systems such as WINDOWS 3.x; WINDOWS 95; WINDOWS 98;WINDOWS 2000; WINDOWS NT 3.51; WINDOWS NT 4.0; WINDOWS CE; WINDOWS XP;and WINDOWS VISTA; the different releases of the Unix and Linuxoperating systems; any version of the MAC OS manufactured by AppleComputer; OS/2, manufactured by International Business Machines; anyembedded operating system; any real-time operating system; any opensource operating system; any proprietary operating system; any operatingsystems for mobile computing devices; or any other operating system. Instill another embodiment, the computing machine 200 can execute multipleoperating systems. For example, the computing machine 200 can executePARALLELS or another virtualization platform that can execute or managea virtual machine executing a first operating system, while thecomputing machine 200 executes a second operating system different fromthe first operating system.

The computing machine 200 can be embodied in any one of the followingcomputing devices: a computing workstation; a desktop computer; a laptopor notebook computer; a server; a handheld computer; a mobile telephone;a portable telecommunication device; a media playing device; a gamingsystem; a mobile computing device; a netbook; a device of the IPODfamily of devices manufactured by Apple Computer; any one of thePLAYSTATION family of devices manufactured by the Sony Corporation; anyone of the Nintendo family of devices manufactured by Nintendo Co; anyone of the XBOX family of devices manufactured by the MicrosoftCorporation; or any other type and/or form of computing,telecommunications or media device that is capable of communication andthat has sufficient processor power and memory capacity to perform themethods and systems described herein. In other embodiments the computingmachine 100 can be a mobile device such as any one of the followingmobile devices: a JAVA-enabled cellular telephone or personal digitalassistant (PDA), such as the i55sr, i58sr, i85s, i88s, i90c, i95c1, orthe im1100, all of which are manufactured by Motorola Corp; the 6035 orthe 7135, manufactured by Kyocera; the i300 or i330, manufactured bySamsung Electronics Co., Ltd; the TREO 180, 270, 600, 650, 680, 700p,700w, or 750 smart phone manufactured by Palm, Inc; any computing devicethat has different processors, operating systems, and input devicesconsistent with the device; or any other mobile computing device capableof performing the methods and systems described herein. In still otherembodiments, the computing device 200 can be any one of the followingmobile computing devices: any one series of Blackberry, or otherhandheld device manufactured by Research In Motion Limited; the iPhonemanufactured by Apple Computer; Palm Pre; a Pocket PC; a Pocket PCPhone; or any other handheld mobile device.

In some embodiments, the computing device 200 may have differentprocessors, operating systems, and input devices consistent with thedevice. For example, in one embodiment, the computing device 200 is aTREO 180, 270, 600, 650, 680, 700p, 700w, or 750 smart phonemanufactured by Palm, Inc. In some of these embodiments, the TREO smartphone is operated under the control of the PalmOS operating system andincludes a stylus input device as well as a five-way navigator device.

In other embodiments the computing device 200 is a mobile device, suchas a JAVA-enabled cellular telephone or personal digital assistant(PDA), such as the i55sr, i58sr, i85s, i88s, i90c, i95c1, or the im1100,all of which are manufactured by Motorola Corp. of Schaumburg, Ill., the6035 or the 7135, manufactured by Kyocera of Kyoto, Japan, or the i300or i330, manufactured by Samsung Electronics Co., Ltd., of Seoul, Korea.In some embodiments, the computing device 200 is a mobile devicemanufactured by Nokia of Finland, or by Sony Ericsson MobileCommunications AB of Lund, Sweden.

In still other embodiments, the computing device 200 is a Blackberryhandheld or smart phone, such as the devices manufactured by Research InMotion Limited, including the Blackberry 7100 series, 8700 series, 7700series, 7200 series, the Blackberry 7520, or the Blackberry Pearl 8100.In yet other embodiments, the computing device 200 is a smart phone,Pocket PC, Pocket PC Phone, or other handheld mobile device supportingMicrosoft Windows Mobile Software. Moreover, the computing device 200can be any workstation, desktop computer, laptop or notebook computer,server, handheld computer, mobile telephone, any other computer, orother form of computing or telecommunications device that is capable ofcommunication and that has sufficient processor power and memorycapacity to perform the operations described herein.

In some embodiments, the computing device 200 is a digital audio player.In one of these embodiments, the computing device 200 is a digital audioplayer such as the Apple IPOD, IPOD Touch, IPOD NANO, and IPOD SHUFFLElines of devices, manufactured by Apple Computer of Cupertino, Calif. Inanother of these embodiments, the digital audio player may function asboth a portable media player and as a mass storage device. In otherembodiments, the computing device 200 is a digital audio player such asthe DigitalAudioPlayer Select MP3 players, manufactured by SamsungElectronics America, of Ridgefield Park, N.J., or the Motorola m500 orm25 Digital Audio Players, manufactured by Motorola Inc. of Schaumburg,Ill. In still other embodiments, the computing device 200 is a portablemedia player, such as the Zen Vision W, the Zen Vision series, the ZenPortable Media Center devices, or the Digital MP3 line of MP3 players,manufactured by Creative Technologies Ltd. In yet other embodiments, thecomputing device 200 is a portable media player or digital audio playersupporting file formats including, but not limited to, MP3, WAV,M4A/AAC, WMA Protected AAC, RIFF, Audible audiobook, Apple Losslessaudio file formats and .mov, .m4v, and .mp4 MPEG-4 (H.264/MPEG-4 AVC)video file formats.

In some embodiments, the computing device 200 comprises a combination ofdevices, such as a mobile phone combined with a digital audio player orportable media player. In one of these embodiments, the computing device200 is a Motorola RAZR or Motorola ROKR line of combination digitalaudio players and mobile phones. In another of these embodiments, thecomputing device 200 is an iPhone smartphone, manufactured by AppleComputer of Cupertino, Calif.

FIGS. 1-3 show a high-level architecture of an illustrative desktopvirtualization system. As shown, the desktop virtualization system maybe single-server or multi-server system, or cloud system, including atleast one virtualization server 106 configured to provide virtualdesktops and/or virtual applications to one or more client accessdevices 140. As used herein, a desktop refers to a graphical environmentor space in which one or more applications may be hosted and/orexecuted. A desktop may include a graphical shell providing a userinterface for an instance of an operating system in which local and/orremote applications can be integrated. Applications, as used herein, areprograms that execute after an instance of an operating system (and,optionally, also the desktop) has been loaded. Each instance of theoperating system may be physical (e.g., one operating system per device)or virtual (e.g., many instances of an OS running on a single device).Each application may be executed on a local device, or executed on aremotely located device (e.g., remoted).

Illustrated in FIG. 4 is one embodiment of a computer device 401configured as a virtualization server in a virtualization environment,for example, a single-server, multi-server, or cloud computingenvironment. The virtualization server 401 illustrated in FIG. 1 can bedeployed as and/or implemented by one or more embodiments of the server106 illustrated in FIG. 1 or the computing devices 200 and 300illustrated in FIGS. 2 and 3. Included in virtualization server 401 is ahardware layer that can include one or more physical disks 404, one ormore physical devices 406, one or more physical processors 408 and aphysical memory 416. In some embodiments, firmware 412 can be storedwithin a memory element in the physical memory 416 and can be executedby one or more of the physical processors 408. The virtualization server401 may further include an operating system 414 that may be stored in amemory element in the physical memory 416 and executed by one or more ofthe physical processors 408. Still further, a hypervisor 402 may bestored in a memory element in the physical memory 416 and can beexecuted by one or more of the physical processors 408. Executing on oneor more of the physical processors 408 may be one or more virtualmachines 432A-C (generally 432). Each virtual machine 432 may have avirtual disk 426A-C and a virtual processor 428A-C. In some embodiments,a first virtual machine 432A may execute, on a virtual processor 428A, acontrol program 420 that includes a tools stack 424. In otherembodiments, one or more virtual machines 432B-C can executed, on avirtual processor 428B-C, a guest operating system 430A-B.

Further referring to FIG. 4, and in more detail, the virtualizationserver 401 may include a hardware layer 410 with one or more pieces ofhardware. In some embodiments, the hardware layer 410 can include one ormore physical disks 404, one or more physical devices 406, one or morephysical processors 408, and one or more memory 416. Physical components404, 406, 408, and 416 may include, for example, any of the componentsdescribed above in FIGS. 1-3. For instance, physical disks 404 mayinclude permanent memory storage, temporary memory storage, disk drives(e.g. optical, floppy, tape), hard disks, external hard drives, flashmemory, network-attached storage, a storage-area network, or any otherstorage repository that the virtualization server 401 can access.Physical devices 406 may include any device included in thevirtualization server 401 and/or any combination of devices included inthe virtualization server 401 and external devices that communicate withthe virtualization server 401. A physical device 406 may be, forexample, a network interface card, a video card, a keyboard, a mouse, aninput device, a monitor, a display device, speakers, an optical drive, astorage device, a universal serial bus connection, a printer, a scanner,a network element (e.g., router, firewall, network address translator,load balancer, virtual private network (VPN) gateway, Dynamic HostConfiguration Protocol (DHCP) router, etc.), or any device connected toor communicating with the virtualization server 401. The physical memory416 in the hardware layer 410 may include any type of memory. Thephysical memory 416 may store data, and in some embodiments may storeone or more programs, or set of executable instructions. FIG. 4illustrates an embodiment where firmware 412 is stored within thephysical memory 416 of the virtualization server 401. Programs orexecutable instructions stored in the physical memory 416 can beexecuted by the one or more processors 408 of the virtualization server401.

Virtualization server 401 may also include a hypervisor 402. In someembodiments, hypervisor 402 may be a program executed by processors 408of the virtualization server 401 to create and manage any number ofvirtual machines 432. The hypervisor 402 can be referred to as a virtualmachine monitor, or platform virtualization software. In someembodiments, a hypervisor 402 can be any combination of executableinstructions and hardware that monitors virtual machines executing on acomputing machine. Hypervisor 402 may be Type 2 hypervisor, or ahypervisor that executes within an operating system 414 executing on thevirtualization server 401. A Type 2 hypervisor, in some embodiments,executes within an operating system 414 environment and virtual machinesexecute at a level above the hypervisor. In many embodiments, the Type 2hypervisor executes within the context of a user's operating system suchthat the Type 2 hypervisor interacts with the user's operating system.In other embodiments, one or more virtualization servers 401 in avirtualization environment may include a Type 1 hypervisor (Not Shown).A Type 1 hypervisor may execute on the virtualization server 401 bydirectly accessing the hardware and resources within the hardware layer410. That is, while a Type 2 hypervisor 402 accesses system resourcesthrough a host operating system 414, a Type 1 hypervisor may directlyaccess all system resources without needing a host operating system 414.Thus, a host operating system 414 may not be present. A Type 1hypervisor may execute directly on one or more physical processors of408 the virtualization server 401, and may include program data storedin the physical memory 416.

The hypervisor 402, in some embodiments, can provide virtual resourcesto operating systems 430 or control programs 420 executing on virtualmachines 432 in any manner that simulates the operating systems 430 orcontrol programs 420 having direct access to system resources. Systemresources can include: physical devices 406; physical disks; physicalprocessors; physical memory 416 and any other component included in thevirtualization server 401 hardware layer 410. In these embodiments, thehypervisor 402 may be used to emulate virtual hardware, partitionphysical hardware, virtualize physical hardware, or execute virtualmachines that provide access to computing environments. In still otherembodiments, the hypervisor 402 controls processor scheduling and memorypartitioning for a virtual machine 432 executing on the virtualizationserver 401. Hypervisor 402 may include those manufactured by VMWare,Inc., of Palo Alto, Calif.; the XEN hypervisor, an open source productwhose development is overseen by the open source Xen.org community;HyperV, VirtualServer or virtual PC hypervisors provided by Microsoft,or others. In some embodiments, a virtualization server 401 executes ahypervisor 402 that creates a virtual machine platform on which guestoperating systems may execute. In these embodiments, the virtualizationserver 401 can be referred to as a host server. An example of such avirtualization server is the XEN SERVER provided by Citrix Systems,Inc., of Fort Lauderdale, Fla.

The hypervisor 402 may create one or more virtual machines 432B-C(generally 432) in which guest operating systems 430 execute. In someembodiments, the hypervisor 402 may load a virtual machine image tocreate a virtual machine 432. In other embodiments, the hypervisor 402may executes a guest operating system 430 within the virtual machine432. In still other embodiments, the virtual machine 432 may execute theguest operating system 430.

In addition to creating virtual machines 432, the hypervisor 402 maycontrol the execution of at least one virtual machine 432. In otherembodiments, the hypervisor 402 may presents at least one virtualmachine 432 with an abstraction of at least one hardware resourceprovided by the virtualization server 401 (e.g., any hardware resourceavailable within the hardware layer 410). In other embodiments, thehypervisor 402 may control the manner in which virtual machines 432access the physical processors 408 available in the virtualizationserver 401. Controlling access to the physical processors 408 mayinclude determining whether a virtual machine 432 should have access toa processor 408, and how physical processor capabilities are presentedto the virtual machine 432.

As shown in the example of FIG. 4, the virtualization server 401 mayhost or execute one or more virtual machines 432. A virtual machine 432is a set of executable instructions that, when executed by a processor408, imitate the operation of a physical computer such that the virtualmachine 432 can execute programs and processes much like a physicalcomputing device. While FIG. 4 illustrates an embodiment where avirtualization server 401 hosts three virtual machines 432, in otherembodiments the virtualization server 401 can host any number of virtualmachines 432. The hypervisor 402, in some embodiments, provides eachvirtual machine 432 with a unique virtual view of the physical hardware,memory, processor and other system resources available to that virtualmachine 432. In some embodiments, the unique virtual view can be basedon any of the following: virtual machine permissions; application of apolicy engine to one or more virtual machine identifiers; the useraccessing a virtual machine; the applications executing on a virtualmachine; networks accessed by a virtual machine; or any other similarcriteria. For instance, the hypervisor 402 may create one or moreunsecure virtual machines 432 and one or more secure virtual machines432. Unsecure virtual machines 432 may be prevented from accessingresources, hardware, memory locations, and programs that secure virtualmachines 432 may be permitted to access. In other embodiments, thehypervisor 402 may provide each virtual machine 432 with a substantiallysimilar virtual view of the physical hardware, memory, processor andother system resources available to the virtual machines 432.

Each virtual machine 432 may include a virtual disk 426A-C (generally426) and a virtual processor 428A-C (generally 428.) The virtual disk426, in some embodiments, is a virtualized view of one or more physicaldisks 404 of the virtualization server 401, or a portion of one or morephysical disks 404 of the virtualization server 401. The virtualizedview of the physical disks 404 can be generated, provided and managed bythe hypervisor 402. In some embodiments, the hypervisor 402 provideseach virtual machine 432 with a unique view of the physical disks 404.Thus, in these embodiments, the virtual disk 426 included in eachvirtual machine 432 can be unique when compared with the other virtualdisks 426.

A virtual processor 428 can be a virtualized view of one or morephysical processors 408 of the virtualization server 401. In someembodiments, the virtualized view of the physical processors 408 can begenerated, provided and managed by the hypervisor 402. In someembodiments, the virtual processor 428 has substantially all of the samecharacteristics of at least one physical processor 408. In otherembodiments, the virtual processor 408 provides a modified view of thephysical processors 408 such that at least some of the characteristicsof the virtual processor 428 are different than the characteristics ofthe corresponding physical processor 408.

FIG. 5 illustrates an example of a cloud computing environment. As seenin FIG. 5, client computers 501-504 may communicate with managementserver 510. Management server 510 may be implemented on one or more thanone physical server. Client computers 501-504 may connect to managementserver 510 via the Internet. In some environments, access to managementserver 510 may be restricted to only client computers on one or morenetworks.

A user of a client computer may, for example, request access to one ormore of the computing resources managed by management server 510.Management server 510 may run, for example, CLOUDSTACK by Citrix Systemor OPENSTACK. It may manage computing resources such as host computers,data storage devices, and networking devices, such as firewalls, networkaddress translators, load balancers, virtual private network (VPN)gateways, Dynamic Host Configuration Protocol (DHCP) routers, and thelike.

A user of a client computer may request access to one of the computingresources managed by management server 510, such as host computer 571. Ahost computer may be, for example, a virtualization server capable ofrunning one or more virtual machines. A user of a client computer mayrequest, for example, access to an existing virtual machine or that avirtual machine be created or destroyed. The physical resources selectedto fulfill a user request may be governed solely by management server510. However, in some embodiments the user may identify a specific hostor request that virtual resources be created within a specific group ofhosts. A management server may allocate resources in the grouprequested, or it may allocate resources in a different group of hoststo, for example, avoid overloading a physical computing resource. Themanagement server then sends the appropriate commands to the selectedresource. For example, the management server may command a host or otherresource to create, start, stop, or delete a virtual machine; to create,alter, or remove virtual disks; to create, alter, or remove virtualnetwork interfaces, etc. These commands may include additional details.For example, a command to create a virtual machine may specify theamount of memory and processing resources it will have available to it,the software that will be included on it, the virtual and/or physicaldisk(s) it will have access to, etc.

In a computing cloud, such as the one managed by management server 510,a zone is a collocated set of physical computing resources. Each zonemay be geographically dispersed from each other zone. For example, zone521 may be located in California, and zone 522 may be located inMaryland. Management sever 510 may be located in a third zone (notshown). Each zone may include an internal network that interfaces withdevices that are outside of the zone, such as management server 510,through a gateway. Users of the computing cloud may be aware of thedistinctions between zones, but they do not need to be aware of thedistinctions. For example, a user may simply request that a virtualmachine having a set amount of memory and processing power be allocated.Management server 510 may present a user with the user interfaceillustrated in FIG. 6, which shows two options (601 and 602) for virtualmachines but does not indicate the location of the physical resourcesthat would be used to create either virtual machine. Alternatively, auser may be able to request that a virtual machine (or other resource)be allocated in a specific zone or subset of a zone.

The cloud illustrated in FIG. 5 allows management server 510 to performall of the administrative tasks for the resources under its control. Byproviding a single interface for managing the resources of the cloud,cloud users may achieve both improved scalability and reducedmaintenance compared to managing resources individually or managinggroups of resources, such as zone 521 or 522, individually. Theinterface provided by management server 510 may be a graphical userinterface, such as the one illustrated in FIG. 6. Other examples ofinterfaces that may be provided by management server 510 includetext-based user interfaces and application programming interfaces(APIs). The interface of management server 510 may be public, therebyallowing anyone to make requests of the management server.

The users of a cloud may be unrelated. For example, users may beaffiliated with different companies, and the information on the virtualmachines or storage of any one user may be hidden from any other user.By sharing a single management server (or set of servers), these usersmay further reduce maintenance costs by effectively sharing the burdenof running management server 510 and the resources it controls.

Some cloud users may wish to have their computing tasks performed onphysical resources that the user controls instead of on the physicalresources provided by a cloud operator. This may be due to, for example,a concern that data on a physical resource of the cloud operator may becompromised and made available to another cloud user. A cloud user mayalso wish to perform computing tasks on its own physical resourcesbecause those resources may be located nearer to the rest of the user'snetwork, thereby enabling faster connections, lower latency, etc.Finally, a cloud user may wish to use its own physical resources becauseit can provide the resources at a lower cost than accessing equivalentresources from the cloud operator.

A cloud user desiring to have computing tasks performed on its ownphysical resources may still take advantage of the improved scalabilityand reduced maintenance of sharing management server 510. The cloud usercan achieve these advantages, by adding its physical resources to thepool of resources managed by management server 510.

FIG. 7 illustrates a cloud computing environment that includes privatezone 523. FIG. 7 depicts the same cloud computing environment as FIG. 5,but private zone 523 has been added. Zone 523 may include the physicalresources of an individual user of the cloud. The hosts in zone 523 maybe integrated with the rest of the cloud and used in the same way as thehosts in zones 521 or 522. For example, management server 510 maycontrol what data is stored in zone 523 and how the physical resourcesof zone 523 are allocated across users. The owner of the hosts in zone523 may be compensated for the computing workloads that managementserver 510 places on the physical resources in zone 523. For example, acloud operator may pay the owner of the hosts in zone 523 for thecomputing workloads of users others that are fulfilled by the resourcesin zone 523.

In some cases, management server 510 may not place computing workloadsfrom other users on the resources of zone 523. In other words, theresources of zone 523 may be reserved exclusively for use by the ownerof the resources. Even where this exclusive arrangement is used, theowner of the resources in zone 523 may achieve the advantages ofmanaging resources via management server 510 and the advantages ofhaving access to the rest of the cloud. For example, the user mayutilize all of the resources in zone 523 but still need access toadditional computing resources. Management server 510 may directrequests for access to additional computing resources to hosts outsideof zone 523, such as to host 571.

As illustrated in FIG. 7, a private zone, such as zone 523, may belocated behind a firewall (541). Firewall 541 may make the hosts of zone523 inaccessible from management server 510. Agent 531 may be used tofacilitate communications between management server 510 and the hosts orother resources of zone 523. Although a single agent (531) isillustrated in FIG. 7, multiple agents may exist. Further, thefunctionality of the agent may be combined with other devices. Forexample, each host of zone 523 may run an instance of the agent, or thefunctionality of the agent may be combined with one or more gateways ornetwork switches. The functionality of the agent may be implemented insoftware, hardware, or a combination thereof.

An agent may be located outside of firewall 541 but be able tocommunicate with the resources within zone 523 due to, for example, arule on firewall 541 allowing incoming traffic from the agent to pass.Alternatively, an agent may be located inside of firewall 541. An agent(531) inside of firewall 541 may still be publically accessible, eventhough the resources of zone 523 might not be. Finally, agent 531 may bepublically inaccessible. However, despite blocking incoming connectionrequests to agent 531, the firewall may allow outgoing communicationsfrom agent 531 to pass. In this case, because management server 510 maynot be able to initiate a connection with agent 531, the agent mayinstead initiate a connection with management server 510. By maintainingthis connection, management server 510 may pass instructions to theresources in zone 523 via the open connection with agent 531. Agent 531may initiate a connection with management server 510 using a certainport or protocol in order to ensure that the agent's outgoingcommunications are not blocked by the firewall. For example, a firewallmay restrict outgoing traffic to certain ports. A firewall may alsoblock outgoing traffic that does not conform to certain protocols. Agent531 may avoid these rules by connecting on commonly used ports and/orusing commonly used protocols. For example, agent 531 may initiate anHTTP connection with management server 510 using port 80. Anotherexample is that agent 531 may initiate an HTTPS connection withmanagement server 510 using port 443. An agent may support multipleprotocols and/or ports for communicating with management server 510. Theprotocols and/or ports used by the agent may be user configurable. Theprotocols and/or ports used by the agent may also be configuredautomatically. For example, if a connection attempt using a firstprotocol and/or port is unsuccessful, the agent may attempt to usedifferent communication protocols and/or different ports until aconnection with management server 510 is established. An example of amethod that may be used to initiate the connection between themanagement server and the agent is described below with reference toFIG. 8.

An agent, such as agent 531, might not provide a management interface.Instead, an agent may merely facilitate management by server 510 byallowing commands from management server 510 to reach the resources of aprivate zone. An agent may translate commands from management server 510into another format, but, unlike management server 510, the agent mightnot generate its own commands for allocating the physical resources ofzone 523. Thus, all of the resources of the cloud illustrated in FIG. 7may be controlled via a single management interface. Interactions withthe management interface may result in management commands being issuedfrom management server 510.

Although a single private zone (523) is illustrated in FIG. 7, a cloudmay contain any number of private zones. Although some private zones maybe associated with a single cloud user, each private zone may beassociated with a different user from each other private zone.

FIG. 8 illustrates a method for adding a private zone to a cloud. Instep 801 the management server creates a token and associates the tokenwith a private zone. This may include, for example, storing rules forhow the private zone may be accessed. For example, only requests fromcertain users may be fulfilled using resources from the private zone.Step 801 may occur in response to a user requesting for authorization toadd a private zone to the cloud via a management interface.

In step 802, the management server sends the token to the cloud user.The token may be sent in the form of a series of bits. The token mayalso be incorporated in agent software. For example, the managementserver may configure agent software with the token and send theconfigured software to the user in step 802.

In step 803, the cloud user configures agent software with the token. Ifthe software was sent to the user pre-configured in step 802, then theuser only needs to run the agent software on an appropriate computer.Otherwise, the user may input the token or otherwise provide the tokento the agent.

In step 804, the management server receives a connection request fromthe agent. By initiating the connection request, the agent avoids thepossibility of communications from the management server being blockedby a firewall. Where an agent is able to receive incoming connectionrequests from the management server, the management server may initiatethe connection. The connection may be a secure connection, such as asecure VPN (virtual private network) connection, an HTTPS (securehypertext transfer protocol) connection, or any other type of secureconnection. The connection may be kept open continuously to allow forcommunications from the management server to be received by the agent atany time.

In step 805, the management server receives the token from the agent.The management server authenticates the agent using the token in step806. This authentication step allows the management server to know thatthe agent, and the resources behind the agent, are in fact authorized toreceive computing workloads from one or more users who interact with themanagement server. Sending computing workloads to an unauthorized agentwould risk exposing a user's potentially sensitive data to unauthorizedparties. The token may be transmitted in its original form. Themanagement server may authenticate the agent by checking that the tokenreceived from the agent matches the token that was sent in step 802.Alternatively, the token may be used as a string that is then digitallysigned by the agent. In this example, the management server mayauthenticate the agent by verifying the token's digital signature. Wherethe token is digitally signed, a new token may be provided to the agentfor signing at the beginning of each connection. Also, where the tokenis digitally signed, steps 801 and 803 may involve configuring themanagement server and agent to use and verify a digital signature.

In step 807, the management server manages the private zone by sendingcommands to resources in the private zone via the agent, such a commandto start a virtual machine. In some instances, these commands mayinclude commands that cause the resources of the private zone toidentify themselves and/or report information about themselves.Information about the resources in the private zone may also be gatheredby the agent and subsequently transmitted by the agent to the managementserver. Examples of the types of additional information that may begathered includes hardware information, such as the amount of memory orprocessing capacity of a host; software information, such as thehypervisor software or other operating system(s) running on a resource;and utilization information, such as information about the virtualmachines or other virtual resources already running or allocated on ahost. While this information may be automatically discovered, some orall of this information may also be input by a user. Updates to theinformation about the resources of the private zone may be transmittedperiodically. The updates may take the form of an entirely new dataset.Alternatively, updates may indicate only information that has changed.

The management server may keep a track of the above-describedinformation about the resources of the private zone using a database. Bykeeping track of each of the resources in the private zone and thehardware, software, and/or utilization information for each resource,the management server may allocate requests for resources appropriately.For example, if one host is running five virtual machines and is low onmemory, the management server may select another host that is runningfewer virtual machines and/or has more memory available. If permitted bythe rules governing the private zone, the host that is selected may belocated in another zone.

Aspects of the disclosure have been described in terms of illustrativeembodiments thereof. Numerous other embodiments, modifications, andvariations within the scope and spirit of the appended claims will occurto persons of ordinary skill in the art from a review of thisdisclosure. For example, one of ordinary skill in the art willappreciate that the steps illustrated in the illustrative figures may beperformed in other than the recited order, and that one or more stepsillustrated may be optional in accordance with aspects of thedisclosure. Modifications may be made by those skilled in the art,particularly in light of the foregoing teachings. For example, each ofthe elements of the aforementioned embodiments may be utilized alone orin combination or sub-combination with elements of the otherembodiments. It will also be appreciated and understood thatmodifications may be made without departing from the spirit and scope ofthe following claims.

1. A method comprising: receiving, at a management server for a cloud ofcomputing resources, a request from an agent to connect a private zoneof computing resources to the cloud; the management server adding thecomputing resources of the private zone to the cloud and maintaining acontinuous communications session between the management server and theagent; and upon receiving, via a publically accessible applicationprogramming interface of the management server, a request to accesscomputing resources of the private zone of the cloud, the managementserver sending instructions for computing resources of the private zoneto the agent via said continuous communications session.
 2. The methodof claim 1, further comprising: upon receiving, via the publicallyaccessible application programming interface, a request to accesscomputing resources of a non-private zone of the cloud, the managementserver sending instructions for computing resources of the non-privatezone to said computing resources without routing the instructionsthrough a continuously-maintained communications session with an agent.3. The method of claim 1, wherein the continuous communications sessionis a secure communications session.
 4. The method of claim 1, furthercomprising: prior to the management server adding the computingresources of the private zone to the cloud, receiving, at the managementserver, a request to authorize the addition of the private zone ofcomputing resources to the cloud, wherein the request is received viathe publically accessible application programming interface of themanagement server; responsive to the request to authorize the additionof the private zone of computing resources to the cloud, the managementserver providing an authentication token for an agent; andauthenticating the agent based on the authentication token, wherein themanagement server adding the computing resources of the private zone tothe cloud is performed only after successful authentication.
 5. Themethod of claim 4, wherein the authentication is performed by receivinga token from the agent and checking whether the received token matchesthe authentication token provided from the management server.
 6. Themethod of claim 4, wherein the authentication is performed by receivinga digitally signed copy of the authentication token and verifying thedigital signature.
 7. The method of claim 1, further comprising: themanagement server denying a second request to access computing resourcesof the private zone of the cloud because the second request was receivedfrom a user that is not authorized to access the private zone.
 8. One ormore tangible computer readable media storing computer-executableinstructions that, when executed, cause a system to perform: receiving,at a management server for a cloud of computing resources, a requestfrom an agent to connect a private zone of computing resources to thecloud; the management server adding the computing resources of theprivate zone to the cloud and maintaining a continuous communicationssession between the management server and the agent; and upon receiving,via a publically accessible application programming interface of themanagement server, a request to access computing resources of theprivate zone of the cloud, the management server sending instructionsfor computing resources of the private zone to the agent via saidcontinuous communications session.
 9. The one or more tangible computerreadable media of claim 8, wherein the instructions also cause thesystem to perform: upon receiving, via the publically accessibleapplication programming interface, a request to access computingresources of a non-private zone of the cloud, the management serversending instructions for computing resources of the non-private zone tosaid computing resources without routing the instructions through acontinuously-maintained communications session with an agent.
 10. Theone or more tangible computer readable media of claim 8, wherein thecontinuous communications session is a secure communications session.11. The one or more tangible computer readable media of claim 8, whereinthe instructions also cause the system to perform: prior to themanagement server adding the computing resources of the private zone tothe cloud, receiving, at the management server, a request to authorizethe addition of the private zone of computing resources to the cloud,wherein the request is received via the publically accessibleapplication programming interface of the management server; responsiveto the request to authorize the addition of the private zone ofcomputing resources to the cloud, the management server providing anauthentication token for an agent; and authenticating the agent based onthe authentication token, wherein the management server adding thecomputing resources of the private zone to the cloud is performed onlyafter successful authentication.
 12. The one or more tangible computerreadable media of claim 11, wherein the authentication is performed byreceiving a token from the agent and checking whether the received tokenmatches the authentication token provided from the management server.13. The one or more tangible computer readable media of claim 11,wherein the authentication is performed by receiving a digitally signedcopy of the authentication token and verifying the digital signature.14. The one or more tangible computer readable media of claim 8, whereinthe instructions also cause the system to perform: the management serverdenying a second request to access computing resources of the privatezone of the cloud because the second request was received from a userthat is not authorized to access the private zone.
 15. A systemcomprising: a management server for a cloud of computing resources,wherein the management server is configured to: receive a request froman agent to connect a private zone of computing resources to the cloud;add the computing resources of the private zone to the cloud andmaintain a continuous communications session with the agent; and uponreceiving, via a publically accessible application programming interfaceof the management server, a request to access computing resources of theprivate zone of the cloud, send instructions for computing resources ofthe private zone to the agent via said continuous communicationssession.
 16. The system of claim 15, wherein the management server isfurther configured to: upon receiving, via the publically accessibleapplication programming interface, a request to access computingresources of a non-private zone of the cloud, send instructions forcomputing resources of the non-private zone to said computing resourceswithout routing the instructions through a continuously-maintainedcommunications session with an agent.
 17. The system of claim 15,wherein the continuous communications session is a secure communicationssession.
 18. The system of claim 15, wherein the management server isfurther configured to: prior to adding the computing resources of theprivate zone to the cloud, receive a request to authorize the additionof the private zone of computing resources to the cloud, wherein therequest is received via the publically accessible applicationprogramming interface of the management server; responsive to therequest to authorize the addition of the private zone of computingresources to the cloud, provide an authentication token for an agent;and authenticate the agent based on the authentication token, whereinadding the computing resources of the private zone to the cloud isperformed only after successful authentication.
 19. The system of claim18, wherein the management server is configured to authenticate theagent by receiving a token from the agent and checking whether thereceived token matches the provided authentication token.
 20. The systemof claim 18, wherein the management server is configured to authenticatethe agent by receiving a digitally signed copy of the authenticationtoken and verifying the digital signature.